Butt the edges of the paper tightly together. Do not overlap and do not leave a gap. Once your wallpaper is in position, gently smooth out any air bubbles or paste bubbles, do not press to hard. As you smooth out the paper wipe it down with a sponge at the same time. The damp surface makes your straight edge glide smoothly over it. Plus you want your work table and the wall clean at all times. Tidy is the name of the game.